As a film forming process, which is a type of semiconductor manufacturing process, there are an Atomic Layer Deposition (ALD) process of alternately supplying a raw material gas and a reaction gas of, for example, oxidizing, nitriding or reducing the raw material gas, a Chemical Vapor Deposition (CVD) process of decomposing a raw material gas in a gas phase or reacting the raw material gas with a reaction gas, and so on. As the raw material gas used in this film forming process, a gas sublimated from the solid raw material may be used to increase a density of a crystal after the film formation and reduce an amount of impurities introduced to a substrate, and is used, for example, in forming a high dielectric film by ALD.
As a raw material supply apparatus using the solid raw material, an apparatus having a configuration in which an inert gas, for example, a carrier gas as a nitrogen gas, is supplied into a raw material vessel surrounded by a heater to supply a sublimated gas together with the carrier gas into a process chamber through a gas supply path, has been known.
However, in sublimating the solid raw material within the raw material vessel and supplying the same, a temperature of a portion sprayed by the carrier gas on a surface of the solid raw material within the raw material vessel, is decreased by heat from evaporation, or an inner wall of the raw material vessel is heated. This causes a temporal change in sublimation efficiency. In particular, when the solid raw material is reduced, the sublimation efficiency of the raw material tends to be lowered. As such, a supply amount of the raw material supplied into a process vessel as a consumption area from the raw material vessel is destabilized. Such a destabilization deteriorates the uniformity of quality or thickness of a thin film between substrates, which results in a reduction in yield. Thus, it is required to establish a technique capable of stably supplying a raw material to a process vessel.